Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262873AbUCRSzK (ORCPT ); Thu, 18 Mar 2004 13:55:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262866AbUCRSzK (ORCPT ); Thu, 18 Mar 2004 13:55:10 -0500 Received: from mx2.elte.hu ([157.181.151.9]:3785 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S262873AbUCRSzD (ORCPT ); Thu, 18 Mar 2004 13:55:03 -0500 Date: Thu, 18 Mar 2004 19:55:48 +0100 From: Ingo Molnar To: Andrew Morton Cc: torvalds@osdl.org, hch@infradead.org, drepper@redhat.com, linux-kernel@vger.kernel.org Subject: Re: sched_setaffinity usability Message-ID: <20040318185548.GA4292@elte.hu> References: <40595842.5070708@redhat.com> <20040318112913.GA13981@elte.hu> <20040318120709.A27841@infradead.org> <20040318182407.GA1287@elte.hu> <20040318103352.1a65126a.akpm@osdl.org> <20040318183944.GA3710@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040318183944.GA3710@elte.hu> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.26.8-itk2 (ELTE 1.1) SpamAssassin 2.63 ClamAV 0.65 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1895 Lines: 52 * Ingo Molnar wrote: > x86-64 has a VDSO page as well, [...] hm, i'm not sure this is the case. It does have a vsyscall page but doesnt fill out AT_SYSINFO. ia64 seems to have something like a vdso, passed down via AT_SYSINFO. We could introduce AT_VDSO to standardize this, and switch x86 from AT_SYSINFO to AT_VDSO, and all architectures that implement the VDSO. I.e. something like the draft patch below. (this would also decrease the size of the auxiliary table - glibc doesnt need to know the exception header address.). (this could also put an end to the AT_ bloat - eg. we could even get rid of some of the constant AT_ values in the future: AT_PAGESZ, AT_CLKTCK, AT_HWCAP, AT_PHENT and AT_FLAGS, and move them into the VDSO?) Ingo --- linux/include/linux/elf.h.orig +++ linux/include/linux/elf.h @@ -162,6 +162,7 @@ typedef __s64 Elf64_Sxword; #define AT_PLATFORM 15 /* string identifying CPU for optimizations */ #define AT_HWCAP 16 /* arch dependent hints at CPU capabilities */ #define AT_CLKTCK 17 /* frequency at which times() increments */ +#define AT_VDSO 18 /* VDSO address */ #define AT_SECURE 23 /* secure mode boolean */ --- linux/include/asm-i386/elf.h.orig +++ linux/include/asm-i386/elf.h @@ -132,10 +132,9 @@ extern int dump_task_extended_fpu (struc #define VSYSCALL_ENTRY ((unsigned long) &__kernel_vsyscall) extern void __kernel_vsyscall; -#define ARCH_DLINFO \ -do { \ - NEW_AUX_ENT(AT_SYSINFO, VSYSCALL_ENTRY); \ - NEW_AUX_ENT(AT_SYSINFO_EHDR, VSYSCALL_BASE); \ +#define ARCH_DLINFO \ +do { \ + NEW_AUX_ENT(AT_VDSO, VSYSCALL_BASE); \ } while (0) /* - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/